Hindsight bias
the tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all along phenomenon.)
Critical thinking
thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions.
Theory
an explanation using an integrated set of principles that organizes and predicts observations.
Hypothesis
a testable prediction
Operational definitions
precise statements of the procedures (operations) used to define independent and dependent variables.
Replication
repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances
Case study
a descriptive research strategy in which one person is studied in great depth
Survey
a technique for ascertaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them.
False consensus effect
is the tendency to overestimate the extent to which others share our beliefs and behaviors.
Population
all the cases in a group, from which samples may be drawn for a study.
Random sample
a sample that fairly represents a population because each member has an equal chance of inclusion.
Naturalistic observation
involves observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.
Correlation
a statistical measure that indicates the extent to which two factors vary together and thus how well one factor can be predicted from the other. Correlations can be positive or negative.
Scatterplot
a depiction of the relationship between two variables by means of a graphed cluster of dots.
Illusory correlation
the false perception of a relationship between two events when none exists.
Experiment
a research strategy in which a researcher directly manipulates one or more factors (independent variables) in order to observe their effect on some behavior or mental process (the dependent variables; experiments therefore make it possible to establish cause-and-effect relationships.
Placebo
an inert substance or condition that is administered as a test of whether an experimental subjects who mistakenly thinks a treatment
Double-blind procedure
a control procedure in which neither the experimenter nor the research subjects are aware of which condition is in effect. It is used to prevent experimenters' and subjects' expectations from influencing the results of an experiment.
Placebo effect
experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which is assumed to be an active agent.
Experimental condition
the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable.
Control condition
the condition of an experiment that contrasts with the experimental condition and serves as a comparison for evaluating the effect of the treatment.
Random assignment
the procedure of assigning subjects to the experimental and control conditions by chance in order to minimize preexisting differences between the groups.
Independent variable
the factor being manipulated and tested by the investigator.
Dependent variable
the factor being measured by the investigator.
Mode
the most frequently occurring score in a distribution; it is the simplest measure of central tendency to determine.
Mean
the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores.
Medians
the middle score in a distribution; half the scores are above it and half are below it.
Range
a measure of variation computed as the difference between the highest and lowest scores in a distribution.
Standard deviation
the average amount by which the scores in a distribution deviate around the mean. Because it is based on every score in the distribution
Statistical significance
a statistical statement of how likely it is that an obtained result occurred by chance.
Culture
the enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next.
Phrenology
Theory that bumps on the skull reflected our mental abilities and personality traits
Neuron
A nerve cell
Dendrite
Receives messages from other cells
Axon
Passes messages away from the cell body to other neurons, muscles, or glands
Myelin Sheath
Covers the axon of some neurons and speeds impulses
Action Potential
A neural impulse that travels down the axon
Threshold
Stimulation required to trigger an impulse
Synapse
Space between the axon tip and the dendrite
Neurotransmitters
Chemical messengers that travel between synaptic gaps
Acetylcholine
Muscle action, learning, and memory
Dopamine
Movement, learning, attention, and emotion
Serotonin
Mood, hunger, sleep, and arousal
Norepinephrine
Alertness and arousal
GABA
Major inhibitory neurotransmitter
Glutamate
Major excitatory transmitter
Endorphins
Opiatelike neurotransmitters linked to pain control and pleasure
Central Nervous System
Brain and spinal cord
Peripheral Nervous System
Sensory and motor neurons that connect the CNS to the rest of the body
Nerves
Neural cables containing many axons
Sensory Neurons
Carry incoming information from the sense receptors to the CNS
Interneurons
CNS neurons that communicate between sensory and motor neurons
Motor Neurons
Carry outgoing information from the CNS to the muscles and glands
Somatic Nervous System
Controls the body's skeletal muscles
Autonomic Nervous System
Controls the glands and muscles of the internal organs
Sympathetic Nervous System
Arouses the body in stressful situations
Parasympathetic Nervous System
Calms the body to conserve energy
Reflex
Simple inborn response to a sensory stimulus
Neural Networks
Interconnected neural cells
Lesion
Tissue destruction
EEG
Amplified recording of electrical brain waves
CT
Series of X-ray photographs
PET
Visual display of brain activity that monitors glucose
MRI
Uses magnetic fields and radio waves to produce computer-generated images
Brainstem
Controls automatic survival functions
Medulla
Controls heartbeat and breathing
Reticular Formation
Controls arousal
Thalamus
Directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
Cerebellum
Coordinates voluntary movement and balance
Limbic System
Associated with emotions and drives for food and sex
Parts of the Lymbic System
Hippocampus, amygdala, and hypothalamus
Amygdala
Linked to emotion
Hypothalamus
Directs several basic maintenance functions and governs the endocrine system via the pituitary
Cerebral Cortex
Ultimate control center
Glial Cells
Support, nourish, and protect neurons
Frontal Lobe
Involved in speaking, muscle movements, and making plans and judgements
Parietal Lobe
Includes the sensory cortex
Occipital Lobe
Includes visual areas
Temporal Lobe
Includes auditory areas
Motor Cortex
Area at frontal lobe that controls voluntary movements
Sensory Cortex
Area at parietal lobe that registers and processes sensations
Association Areas
Areas not involved with motor or sensory functions that are involved with higher mental functions
Aphasia
Impairment of language
Broca's Area
Controls language expression through directing muscle movements involved in speech
Wernicke's Area
Involved in language comprehension and expression
Corpus Callosum
Neural fibers connecting the two hemispheres
threadlike structures made of DNA that contain the genes
Chromosomes
complex molecule containing the genetic information that makes up the chromosomes
DNA
biochemical units of heredity that make up the chromosomes
a segment of DNA capable of synthesizing a protein
Genes
the complete instructions for making an organism
consisting of all the genetic material in its chromosomes
Genome
the principle that, among the range of inherited trait variations, those that lead to increased reproduction and survival will most likely be passed on to succeeding generations
Natural Selection
random errors in gene replication that lead to a change in the sequence of nucleotides
the source of all genetic diversity
Mutations
the study of the evolution of behavior and the mind, using the principles of natural selection
Evolutionary Psychology
in psychology, the characteristics, whether biologically or socially influenced, by which people define male and female
Gender
study of the relative power and limits of genetic and environmental influences on behavior
Behavior Genetics
every nongenetic influence, from prenatal nutrition to the people and things around us
Environment
develop from separate eggs genetically no closer than brothers and sisters, but they share the fetal environment
Fraternal Twins